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Tandem Fabry -Perot Spectrometer SQUEAN: S pectrometer for QU asar in EA rly u N iverse

Tandem Fabry -Perot Spectrometer SQUEAN: S pectrometer for QU asar in EA rly u N iverse. Presented at The 2 nd Survey Science Group Workshop, High1 Resort on 2012 Feb 14 by Soojong Pak (Kyung Hee University). Classification of Spectrometers. Types of Dispersing Elements.

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Tandem Fabry -Perot Spectrometer SQUEAN: S pectrometer for QU asar in EA rly u N iverse

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  1. Tandem Fabry-Perot SpectrometerSQUEAN: Spectrometer for QUasar in EArlyuNiverse Presented at The 2nd Survey Science Group Workshop, High1 Resort on 2012 Feb 14 by Soojong Pak (Kyung Hee University)

  2. Classification of Spectrometers

  3. Types of Dispersing Elements

  4. Slit Sp. vs. Imaging Sp. Imaging Spectrometer Slit Spectrometer

  5. Spatial Direction Spatial Direction Spatial Direction DATA Format Imaging Spectrometer Slit Spectrometer

  6. Other Kinds of Imaging Spectrometer: Integral Field Unit

  7. Other Kinds of Imaging Spectrometer:Multi-Object Spectrometer

  8. What is Fabry-Perot Spectrometer?

  9. Fabry-Perot Parameters Path Difference Finesse m = 1 2 3 ….

  10. Basic Etalon Equations • Conventions • : Spectral Resolution • We assumed that the incident angle is zero, and the mirror space is in vacuum, • It is convenient to use wave numbers, . • : mirror distance for at order m • : Free Spectral Range in units of wave number • : Corresponding mirror distance for FSR at m • : Full Width at Half Maximum of the instrument profile in units of wavelength • : Corresponding mirror distance for • Etalon Equations

  11. m=7 m=8 m=9 m=10 m=11 m=12 m=13 FSR Simulated Spectra 10 um 5 um

  12. Simulated Spectra Order Sorting Filter 10 um 5 um

  13. Simulated Spectra 10 um 5 um

  14. Telescope Camera Lens Collimator Detector FP-B (m=250) FP-A (m=20) Order Sorting Method ofTandem Fabry-Perot

  15. Spatial Direction Spatial Direction Spatial Direction Disadvantage of FP Takes Long Time for Wide Spectral Band

  16. Spatial Direction Spatial Direction Spatial Direction Advantage of FP Takes Many Targets for Short Spectral Band

  17. Suggested Fabry-Perot Spectrometer

  18. Specifications • Target Emission Lines at Optical Bands • [OII] 372.7nm • H486.1nm • [O III] 495.9 500.7nm • H656.2 nm • [SII] 671.6 673.1 nm • Spectral Resolutions • The spectral resolution R = Finesse X m, where Finesses comes from the FP mirrors reflectivity and the order of interference, m, from the mirrors distance. • If Finesse=40 and m=50-250, we can expect that R = 2000 – 10000 • FOV (in case we use CQUEAN CCD) • 13 um 1024 X 1024 • Total FOV 5 X 5 arcmin with 0.27 arcsec/pixel

  19. Sciences (1/2) • Emission Lines of Star Forming Regions in the Galaxy (Soojong Pak) • Emission Lines of Star Forming Regions in the nearby galaxies (Luis Ho suggested) • Emission Lines of Merging AGNs (Julia Comerford suggested) • Ref. Comerford et al. 2012, ApJ, 753, 42, Kpc-Scale Spatial Offsets in Double-Peaked Narrow-Line AGN. I • Ref. Liu et al. 2011, ApJ, 737, 101, AGN Pairs from the SDSS. I. • Narrow Emission Line Survey of Galaxies at z=1. • H_beta 486nm, [OII] 372.7nm • Ref. Glazebrook et al. 2004, AJ, 128, 2652, Cosmic Star Formation History to z=1 from Narrow Emission Line Selected Tunable Filter Survey

  20. Sciences (2/2) • Dark Matter in Globular Clusters (Karl Gebhardt) • 1000 Stellar velocities at the edges of the visible clusters in order to constrain the dark matter distributions. • R=10000 for velocity accuracy of 1 km/s • m_R = 20 – 21 mag • Chemical Composition Studies in Globular Cluster (Chris Sneden) • a search for (the rare) Li-rich giant stars.  The Li I resonance line is at 6708A • characterizing Na variations in clusters.  One could choose Na D lines, but probably I would be happier with one of the 5680A doublet lines. • searching for Ba abundance variations.  Probably the 6496A or 6141A lines are best. • finding out the level of metallicity variations as a function of evolutionary state.  One could use one of the Ca IR triplet lines, for example.

  21. McDonald Observatory Otto Struve 2.1m telescope 2011 IR Workshop

  22. CQUEAN at 2.1m telescope Science CCD Filter Wheel Control PC Guide CCD Motor for guide CCD field rotator Guide CCD field rotator 2011 IR Workshop

  23. Science CCD Camera (AndoriKon-M 934 BR-DD) 2011 IR Workshop

  24. Possible Designs of Tandem Fabry-Perot Serial Configuration of 2 etalons FP-B (m=250) FP-A (m=20) Integrated Configuration of 3 mirrors

  25. Etalon Specifications for Tandem Fabry-Perot • Basic Specifications • We use two etalons for high spectral resolution (ET-H) and low spectral resolution (ET-L). • The ET-L will sort the overlapped orders of ET-H. • We also need broad band filters for the overlapped orders of ET-L. • The mirror sets and housing of ET-H and ET-L are identical. The only difference is the mirror distances. • Etalon Specs

  26. Telescope Camera Lens Collimator Detector FP-A (m=150) FP-B (m=10) Fore-Optics Design • We need collimator units and camera units • before and after the Fabry-Perot.

  27. Fore-Optics Design with Traditional Lens System Example from CQUEAN Focal Reducer

  28. Fore-Optics Design with Off-Axis Mirrors • We can apply the off-axis mirror design of Dr. Seunghyuk Chang. Eccentric section of an on-axis parent system The mirrors of a confocal system do not need to have a common axis for a perfect image at the system focus

  29. Re-imaging Optics for KASINICS(cf. Offner System)

  30. Schwartzschild-Chang Type Telescope - from "Inverse Cassegrain" - ellipsoid paraboloid off-axis (Schwartzschild-Chang Type) D=50mm, F/D=2et al. 2011 (Kim, Pak, Chang et al. 2010) on-axis (Schwartzschild Type)

  31. Off-Axis Design for SQUEAN (by Chang)

  32. Off-Axis Design for SQUEAN (by Chang)

  33. Spot Diagrams (x,y) 13um

  34. Project Roadmap and Required Resources Cost includes HW and Travel.

  35. Appendix

  36. Fabry-Perot Etalon Vendors • Bristol Instruments • They make the replacement FP mirrors for OLD Burleigh RC series. • The basic price for one set of mirrors starts from $8,000. • The man in the company recommends www.lightmachinery.com for custom-made etalons. • LightMachinery.com

  37. Etalon • LightMachinery.com • They make customized Etalon mirrors. • Piezo Tunable Etalons with clear aperture of 4 mm. • Ian Miller, Director of R&D, gives very kind detailed technical supports.

  38. PZT Tunable Etalon Housing • ThorLabs.com • Scanning Fabry-Perot Interferometer: SA210-5B • 535-820 nm, 10 GHz FSR • $2,533 • This is for laser, but we can use this for scanning test. • PZT Drives & Actuator: PE4 • Micrometer Travel Range = 4mm with 1 um resolution • PZT Travel Range = 15 um with 10 nm resolution • 3 X $479.60 / unit • Open-Loop PZT Controllers: MDT693A • 3 Channel • $1,580 • Piezoelectric Actuators • Open Loop Piezo Actuator, 17um/150V: AE0505D16F, $153 • Full Bridge Strain Gauge Piezo Actuators, AE0505D16F: PZS001, $175 • Strain Gauge Amplification Circuit, AMP002, $161 • www.PhysikInstrumente.com

  39. Coefficient of Thermal Expansion • Fused Silica • CTE = 0.55 ppm/K • Invar • CTE = 0-2 ppm/K • Piezo Material • CTE = 6E-3/K http://www.piceramic.com/datasheet/Piezo_Material_Datasheet_Cofefficients_Temperature_Measurements.pdf

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